A scalpel is a small knife, typically with a removable blade, that is used in medical, veterinary, biological, and other procedures to cut a workpiece. Scalpel blades used in medical, veterinary, and biological procedures must be very sharp so as to inflict as little damage as possible to the tissue being cut. They must retain that sharpness for as long as possible during a procedure to minimize the number of instrument changes during the procedure.
Conventional scalpel blades are made of a surgical grade stainless steel that is hardened to a Rockwell C hardness of about 54-62 in order to retain the sharpness of their cutting edges throughout a procedure. They are sharpened to an included blade angle that is typically about 26 degrees. It would be desirable to reduce the included blade angle so as to increase the sharpness of the scalpel blade. The result of such a reduction of the included blade angle is to increase the tendency of the blade to bend and roll over, rendering it ineffective. The blade also has a tendency to break during a procedure, because the high hardness results in a low ductility and toughness that render the very thin blade susceptible to brittle failure. Brittle failure is of particular concern during surgery because the broken piece of the scalpel blade is difficult to find and may be retained within the body of the patient. The reduction in the included blade angle of conventional scalpel blades also causes the blades to become dulled very quickly during service.
On the other hand, the stainless steel may be annealed to reduce the Rockwell C hardness to a level where the blade has reasonable toughness and a reduced tendency to brittle fracture. The result is that the tapered region of the blade still has a rollover tendency that can render it ineffective. Further, because the steel is softer and does not hold an edge as well, the service life of the sharp edge is greatly reduced so that only a few cuts may be made before the scalpel blade must be replaced.
There is a need for an improved scalpel and scalpel blade which has an increased sharpness that is retained for an extended period of time, yet is not susceptible to brittle fracture during a procedure. The present invention fulfills this need, and further provides related advantages.